ChatterBank1 min ago
Plumbing Query
35 Answers
In a bungalow the hot feed to both kitchen and bathroom is not powerful (to say the least). I went into the loft to try to measure/estimate distances. I reckon the bottom of the cold header tank is 2.5" above the top of the hot water cylinder; and although I have to guess the thickness of the kitchen ceiling I reckon the bottom of the hot water cylinder must be about 63.5" above the taps.
I tried to find out if this was ok but there seems to be some rule about not having that information on the internet. The best I could find was, suggestions of 0" to 3" for the former distance, and 80" for the latter. Does this sound correct, and could the inability to increase the fall be the cause of the issue ?
(I did try to unblock any potential airlocks first. Messy business on combination taps :-( which seemed to help slightly (may have been my imagination) but has not solved anything.)
Cheers.
I tried to find out if this was ok but there seems to be some rule about not having that information on the internet. The best I could find was, suggestions of 0" to 3" for the former distance, and 80" for the latter. Does this sound correct, and could the inability to increase the fall be the cause of the issue ?
(I did try to unblock any potential airlocks first. Messy business on combination taps :-( which seemed to help slightly (may have been my imagination) but has not solved anything.)
Cheers.
Answers
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OG
Sounds like a prime candidate for a combi...I know you said it is difficult, but the difference it makes is really worth the effort - and the cost. There's no harm in getting a couple of estimates, I would recommend Vaillant who have excellent products and well trained dealers to install them. British Gas would also do it, typically for double the cost, despite their "half price boiler" ads.
Sounds like a prime candidate for a combi...I know you said it is difficult, but the difference it makes is really worth the effort - and the cost. There's no harm in getting a couple of estimates, I would recommend Vaillant who have excellent products and well trained dealers to install them. British Gas would also do it, typically for double the cost, despite their "half price boiler" ads.
What I would add, OG, is that should you decide to do the minimum and install a pump just for the kitchen and bathroom hot taps, don’t overdo it. You don’t need loads of pressure just for those taps - 1 bar for example would be more than enough. I only say this because increased pressure tests the plumbing installation more and with a higher pressure you might find problems you didn’t know you had.
Update. She spoke to a plumber, who had done previous work on the premises, for an opinion. He has just been and he mentioned the combi, and she said she wasn't keen. All eggs in one basket etc..
Shows that I misunderstand; I thought the important drop was from the hot cylinder to the taps, he was saying it was from the header to the cylinder, but looking again on the Net it now seems the important drop is from the cold header tank to the taps. Arrhhhh.
He mentioned that the flexible connections at the sink and basin restricted flow, and suggested the main problem is the kitchen sink and a new tap might help a bit. We're unhappy with the existing tap anyway so no issue with replacing it.
No suggestion of a pump though, and I wasn't going to suggest to grandma how to suck eggs. Puzzled it wasn't considered though.
I've just been back into the loft; yes the hot pipe does have a tap in line. Are they as bad as isolation valves ? This was one of the type with a flower shaped 'knob'. It was fully open. I was wondering if it was causing issues. Would it help if it was replaced (I'm assuming it's there for a reason) with one of the bar handle types ?
Shows that I misunderstand; I thought the important drop was from the hot cylinder to the taps, he was saying it was from the header to the cylinder, but looking again on the Net it now seems the important drop is from the cold header tank to the taps. Arrhhhh.
He mentioned that the flexible connections at the sink and basin restricted flow, and suggested the main problem is the kitchen sink and a new tap might help a bit. We're unhappy with the existing tap anyway so no issue with replacing it.
No suggestion of a pump though, and I wasn't going to suggest to grandma how to suck eggs. Puzzled it wasn't considered though.
I've just been back into the loft; yes the hot pipe does have a tap in line. Are they as bad as isolation valves ? This was one of the type with a flower shaped 'knob'. It was fully open. I was wondering if it was causing issues. Would it help if it was replaced (I'm assuming it's there for a reason) with one of the bar handle types ?
"Gate Valves" have flower-shaped tap head and are designed for use with indirect water systems ie, systems fed via a header tank. "Stop Cocks" have bar handles and are designed for use with direct water systems ie, kitchen cold taps, refilling header tanks etc. Stop cocks rely on water pressure to lift the washer when the tap is turned on, so can fail to operate on an indirect system as the pressure may not be great enough.
Gate valve work by pushing a slug of metal into the water-flow and pulling it back out again when you turn the tap back on. They require no pressure to operate them and, if you use them on a direct system, can allow a small flow of water even when turned off. Only a trickle and enough to work on the system but relying on them not to allow any water to pass through over a long period can result in a flood.
Changing the type of tap could get you into a situation where you turn-on the tap but the water cannot flow. DON'T DO IT.
Gate valve work by pushing a slug of metal into the water-flow and pulling it back out again when you turn the tap back on. They require no pressure to operate them and, if you use them on a direct system, can allow a small flow of water even when turned off. Only a trickle and enough to work on the system but relying on them not to allow any water to pass through over a long period can result in a flood.
Changing the type of tap could get you into a situation where you turn-on the tap but the water cannot flow. DON'T DO IT.
Been thinking about the difference with the bungalow and other places I've lived, particularly with consideration over past bathrooms, which being upstairs ought to have exhibited the same issues as the bungalow; as it was a single storey drop between the cold tank in the loft, and the taps.
Does the size of the cold tank make a difference to the pressure and thus flow ? In the bungalow it's quite small, about the size of a medium sized crate; whereas in past houses they were much bigger and would have held a lot more water.
Does the size of the cold tank make a difference to the pressure and thus flow ? In the bungalow it's quite small, about the size of a medium sized crate; whereas in past houses they were much bigger and would have held a lot more water.
Apart from the layout of the plumbing (size of pipes, length, number of bends etc), the only factor affecting the water pressure is the "head" of water ie, the difference between the tap and the level of water in the header tank. A bigger header tank gives you more capacity but does not affect the pressure.
As the water level in the header tank drops the pressure will drop and will be particularly noticeable if the head is small in the first place (as yours is). Perhaps it's worth checking that the header tank is filling nearly up to the overflow pipe - it can be easily adjusted.
PS O_G - has anybody else told you you've got a small head?
As the water level in the header tank drops the pressure will drop and will be particularly noticeable if the head is small in the first place (as yours is). Perhaps it's worth checking that the header tank is filling nearly up to the overflow pipe - it can be easily adjusted.
PS O_G - has anybody else told you you've got a small head?
Doubt anyone's still reading but...
Turns out there's two small cold tanks. Too little space and too much insulation to get a good view of how everything is, lord only knows how they worked up there to fit it. Looks like the one inaccessible at the back tops up the slightly lower one at the front ? Weird. She wondered if it was to do with the defunct solar panels further slong, but I don't think so.
Both cold tanks seem filled to just under the overflow.
She's decided to get the kitchen tap replaced first; if the plumber ever gets back to her.
Turns out there's two small cold tanks. Too little space and too much insulation to get a good view of how everything is, lord only knows how they worked up there to fit it. Looks like the one inaccessible at the back tops up the slightly lower one at the front ? Weird. She wondered if it was to do with the defunct solar panels further slong, but I don't think so.
Both cold tanks seem filled to just under the overflow.
She's decided to get the kitchen tap replaced first; if the plumber ever gets back to her.
Gate valves (red handwheel ) are full-flow, OG. No problem here.
As with service valves, braided hoses generally do not work well with gravity systems. The bore is only a few millimetres, severely restricting flow.
A lot of modern taps give the same problem... a very small bore.
Something like this is better, although it still needs 1 bar.......
https:/
Older systems such as gravity ones work best with old-fashioned, separate taps with conventional handwheels and washers.
As with service valves, braided hoses generally do not work well with gravity systems. The bore is only a few millimetres, severely restricting flow.
A lot of modern taps give the same problem... a very small bore.
Something like this is better, although it still needs 1 bar.......
https:/
Older systems such as gravity ones work best with old-fashioned, separate taps with conventional handwheels and washers.
OG does have central heating as he asked about turning his heating off a few weeks ago.
From my many sorties into other peoples lofts I do recall that most gate valves are seized and often only partially turn but give the impression of being wide open or closed.
It is just a thought but does the gate valve move quite a long way when opened and closed, or is it just a few turns. It may well be partially seized in a slighly closed position. They seize because they are never used from one years end to the next. May be worth a try.. it wont cost anything if it isn't seized.
Brute force is usually the answer to
From my many sorties into other peoples lofts I do recall that most gate valves are seized and often only partially turn but give the impression of being wide open or closed.
It is just a thought but does the gate valve move quite a long way when opened and closed, or is it just a few turns. It may well be partially seized in a slighly closed position. They seize because they are never used from one years end to the next. May be worth a try.. it wont cost anything if it isn't seized.
Brute force is usually the answer to
Wow, just noticed 3 more posts :-) Whoops.
Thanks all.
Her plumber didn't get back to her after they discussed the kitchen tap and she suggested a different one that she preferred. :-(
My property with the c/h is different to the property being discussed here. Here heating is from a back boiler. But as mentioned, the two cold tanks seem joined.
I can retry the valve again but not for a few days hence.
Cheers.
Thanks all.
Her plumber didn't get back to her after they discussed the kitchen tap and she suggested a different one that she preferred. :-(
My property with the c/h is different to the property being discussed here. Here heating is from a back boiler. But as mentioned, the two cold tanks seem joined.
I can retry the valve again but not for a few days hence.
Cheers.
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